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Finding the Fourth Proportional to 78.39, 108.15 and 49.26

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Solution

The fourth proportional to 78.39, 108.15 and 49.26 is: 67.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.39 : 108.15 = 49.26 : x
  2. Step 2: Convert to fraction form
    78.39/108.15 = 49.26/x
  3. Step 3: Cross multiply
    78.39x = 108.15 × 49.26
  4. Step 4: Simplify right side
    78.39x = 5,327.47
  5. Step 5: Solve for x
    x = 5,327.47/78.39
  6. Step 6: Final answer
    x = 67.96

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.